1. Field of the Invention
This invention relates to a reforming catalyst for partial oxidation of a hydrocarbon compound containing a sulfur compound and to a method for the reforming.
2. Description of the Related Art
The hydrogen-containing gas which mainly includes hydrogen and carbon monoxide is widely utilized as the raw material for reducing gas and also for various chemical products besides the production of hydrogen gas. Recently, the feasibility study of using this gas as the fuel for a fuel cell is now under way. The hydrogen-containing gas is obtained by the reforming of a hydrocarbon compound and the method of partial oxidation of hydrocarbon represented by the following formula is available for this method of reforming.CH4+1/2O2→2H2+CO
The method for partial oxidation of hydrocarbon consists in producing a hydrogen-containing gas by partially oxidizing the hydrocarbon with an oxygen-containing gas such as air in the presence of a catalyst. The preceding formula represents the reaction of partial oxidation using methane as the hydrocarbon.
For this reaction of reforming, methods which includes deriving hydrogen from methanol, LP gas, natural gas, gasoline, gas oil, and coal oil and putting the hydrogen to use have been available. From the infrastructural point of view, the town gas is thought to be one of the fuels that near the practical use. The town gas and the LP gas, however, contain sulfur components such as mercaptan and, when directly introduced, pose such problems as poisoning a reforming catalyst and a CO removing catalyst and suffering from degradation of performance.
As means to avoid these problems caused by sulfur components, various preventive measures have been proposed such as, for example, a method which includes having a desulfurizing device additionally disposed, using this device to remove the sulfur components, and subjecting the source gas emanating from the device to a process for partial oxidation. When such a preventive measure is adopted, the additionally disposed device results in incurring cost of installation and cost of maintenance and inevitably entails a new problem of boosting the cost of production.
In JP-2002-121006A, a catalyst having platinum supported on a zirconia type mixed oxide is proposed as a catalyst repressing degradation of catalysis by sulfur poisoning in the reaction of reforming a sulfur compound-containing hydrocarbon. JP-2002-121006A mentions that the reaction of partial oxidation has serious degradation of performance, and the inclusion of water and air in the source gas is necessary for securing durability to withstand the sulfur poisoning.